This invention relates to a novel method of preparing omega-carboxyalkanohydroxamic acids and particularly to the preparation of omega-carboxyalkanohydroxamic acids from salts of nitrocycloalkanones.
Carboxyalkanohydroxamic acids can be prepared by reacting an omega-dicarboxylic acid with hydroxylamine hydrochloride. The reaction product resulting from this method, however, provides a mixture of unreacted omega-dicarboxylic acid, omega-dihydroxamic acids and the desired carboxyalkanohydroxamic acid. The mixture of products and reactants obtained by such a method renders it difficult and costly to recover the desired product even when complicated purification steps are employed. In the instance where a mixture of carboxyalkanohydroxamic acids is the desired product and preparation of the same is undertaken employing a mixture of omega-dicarboxylic acids, separation and recovery of desired product is extremely difficult. We have now found a method whereby a range of individual or mixtures of omegacarboxyalkanohydroxamic acids can be produced in exceptionally good yields and in high purities.